import java.util.ArrayList;
import java.util.List;

public class Test {
    public static void EASYdelete(){
        ArrayList<Character> list =new ArrayList<>();
        String s1="welcome to bit";
        String s2= "come";
        for (int i = 0; i < s1.length(); i++) {
            char ch=s1.charAt(i);
            if(!s2.contains(ch+"")){
                list.add(ch);
            }
        }
        for (int i = 0; i < list.size(); i++) {
            System.out.print(list.get(i));
        }

    }

    public static void main(String[] args) {
        //EASYdelete();



    }
    public static double fun(double a,double b ){
        return a/b;
    }
    public static void main9(String[] args) {

        ArrayList<Integer> arrayList=new ArrayList<>();
        arrayList.add(1);
        arrayList.add(1);
        arrayList.add(2);
        arrayList.add(3);
        arrayList.add(4);
        System.out.println(arrayList.toString());
        //截取arraylist部分
        List<Integer> arrayList1= arrayList.subList(0,5);
        //arraylist1截取部分指向和arraylist相同的堆区
        System.out.println(arrayList1.toString());
        arrayList1.set(0,99);
        System.out.println(arrayList1.toString());
        System.out.println(arrayList.toString());

    }
}
